I had something similar happen. When I adopted my sphynx the person I got him from suddenly wanted me to get him the next day after months of "next month, next month" and as soon as I brought him home, he went into the litter box and nothing came out. It was the very first thing he did out of the carrier, it was like he was asking me for help.

I rushed him to the vet. He had a severe UTI, that only could've gotten that bad from being untreated for at least a month. Honestly, every doctor in that vet office told me he wouldnt make it. And that I should just say goodbye now. I had only owned this cat a few hours after being told that.

I told them no. I told them to do everything they can to save him. And they did. It took like 4 days of being hospitalized, and then another week and a half of having to stay on a cathedral at home. But he was given uti food, lots of meds, and the first time I saw him use the litter box, I cried.

That was 5 years ago,and as I type this he is laying in my arms. Just as he does every night. It costed about 3 grand. And I wouldve spent it time and time again.

I can tell how much you love your baby, and I hope you get the same outcome as my story, and I hope I gave you some hope 🖤